ZnO·WO3悬浮水溶液中SO2的光催化氧化

本文考察了ZnO·WO₃悬浮水溶液中污染物SO₂的可见光催化氧化并建议通空气处理较高浓度的SO₃^2-扩水溶液。含0.15mol/LSO₃^2-水溶液可见光照2h可将SO₃^2-基本上光催化氧化成SO₄^2-。对这光助SO₃^2-自发氧化反应中可能平行存在的自发、多相催化、光化学和光催化等反应进行实验对比;筛选出克分子比0.5ZnO·WO为最佳掺杂配比;考察了光催化剂热处理、空气流量、pH对光催化活性的影响,得出pH7.5为最佳值;太阳光催化SO₃^2-氧化速率比室内实验更快,展现了利用太阳能于环保的应用前景,对所有实验结果都给以理论解释,并提出一个较详细的反应机理。

PHOTOCATALYTIC OXIDATION OF SO2 IN AQUEOUS SUSPENSION OF ZnO.WO3

The photocatalytic oxidation of pollutant SO₂ in aqueous suspension of ZnO·WO₃ under visible light irradiation was investigated and an air flowing was proposed to treatconcentrated SO₃^2- solution. The SO₃^2-,contained in an aqueous solution of 0.15 mol/L,was almost photocatalytically oxidized to produce SO₄^2- within 2h irradiation.In photoassisted spontaneous oxidation of SO₃^2-,such coexistent reactions as spon-taneous,heterogeneously catalytic,photochemical and photocatalytic reactions hclVe beencompared by experiments.Gram molecular ratio 0.5 ZnO·WO₃ was chosen to be the opti-mal doping ratio.The effect of the heat treatment of photocatalyst,air flowing and pH onphotocatalytic activity has been determined and pH7.5 was identified to be the optimal.Solar photocatalytic oxidation of SO₃^2- shows the faster reaction rate than that in indoorexperimentst which develops a better prospects for the application of solar photocatalysisto environmental protection,All experimental results are explained in theory.A reactionmechanism has been proposed in detail.